This topic provides an overview of setup steps that you need to follow when configuring your Fibre Channel SAN environment to work with ESXi. In preparation for configuring your Fibre Channel SAN and setting up the ESXi system, review the requirements and recommendations.

ESXi Fibre Channel SAN Requirements

  • Make sure that ESXi systems support the SAN storage hardware and firmware combinations you use. For an up-to-date list, see the VMware Compatibility Guide.
  • Configure your system to have only one VMFS volume per LUN.
  • Unless you are using diskless servers, do not set up the diagnostic partition on a SAN LUN.

    If you use diskless servers that boot from a SAN, a shared diagnostic partition is appropriate.

  • Use RDMs to access raw disks. For information, see Raw Device Mapping in vSphere.
  • Make sure that the storage device driver specifies a large enough queue. You can set the queue depth for the physical HBA during a system setup.
  • VMtools increases the default disk timeout SCSI TimeoutValue parameter to 180 seconds. On virtual machines without VMtools, increase the value of the SCSI TimeoutValue parameter. With this parameter set up, the VMs can better tolerate delayed I/O resulting from a path failover. For information, see Path Failover and Virtual Machines or the KB 1009465.

ESXi Fibre Channel SAN Restrictions

When you use ESXi with a SAN, certain restrictions apply.

  • ESXi does not support FC connected tape devices.
  • You cannot use multipathing software inside a virtual machine to perform I/O load balancing to a single physical LUN. However, when your Microsoft Windows virtual machine uses dynamic disks, this restriction does not apply. For information about configuring dynamic disks, see Set Up Dynamic Disk Mirroring for Virtual Machines on vSphere VMFS.

Setting LUN Allocations

This topic provides general information about how to allocate LUNs when your ESXi works with SAN.

When you set LUN allocations, be aware of the following points:

Storage provisioning
To ensure that the ESXi system recognizes the LUNs at startup time, provision all LUNs to the appropriate HBAs before you connect the SAN to the ESXi system.

Provision all LUNs to all ESXi HBAs at the same time. HBA failover works only if all HBAs see the same LUNs.

vMotion and VMware DRS
When you use vCenter Server and vMotion or DRS, make sure that the LUNs for the virtual machines are provisioned to all ESXi hosts. This action provides the most ability to move virtual machines.
Active-active compared to active-passive arrays
When you use vMotion or DRS with an active-passive SAN storage device, make sure that all ESXi systems have consistent paths to all storage processors. Not doing so can cause path thrashing when a vMotion migration occurs.

For active-passive storage arrays not listed in Storage/SAN Compatibility, VMware does not support storage port failover. In those cases, you must connect the server to the active port on the storage array. This configuration ensures that the LUNs are presented to the ESXi host.

Setting Fibre Channel HBAs

Typically, FC HBAs that you use on your ESXi host work correctly with the default configuration settings.

You should follow the configuration guidelines provided by your storage array vendor. During FC HBA setup, consider the following issues.
  • Do not mix FC HBAs from different vendors in a single host. Having different models of the same HBA is supported, but a single LUN cannot be accessed through two different HBA types, only through the same type.
  • Ensure that the firmware level on each HBA is the same.
  • Set the timeout value for detecting a failover. To ensure optimal performance, do not change the default value.
  • ESXi supports 32 Gbps end-to-end Fibre Channel connectivity.

Configuring Fibre Channel over Ethernet

To access Fibre Channel storage, an ESXi host can use the Fibre Channel over Ethernet (FCoE) protocol. The FCoE protocol encapsulates Fibre Channel frames into Ethernet frames. As a result, your host does not need special Fibre Channel links to connect to Fibre Channel storage. The host can use 10 Gbit lossless Ethernet to deliver Fibre Channel traffic.

Fibre Channel over Ethernet Adapters

VMware supports hardware FCoE adapters, a specialized offloaded Converged Network Adapters (CNAs) that contain network and Fibre Channel functionalities on the same card.

When such adapter is installed, your host detects and can use both CNA components. In the vSphere Client, the networking component appears as a standard network adapter (vmnic) and the Fibre Channel component as a FCoE adapter (vmhba).

For information on adapters that can be used with VMware FCoE, see the VMware Compatibility Guide

Setup Workflow

This topic provides an overview of installation and setup steps that you need to follow when configuring your Fibre Channel SAN environment to work with ESXi.

Follow these steps to configure your ESXi SAN environment.

  1. Design your SAN if it is not already configured. Most existing SANs require only minor modification to work with ESXi.
  2. Check that all SAN components meet requirements.
  3. Perform any necessary storage array modification.

    Most vendors have vendor-specific documentation for setting up a SAN to work with VMware ESXi.

  4. Set up the HBAs for the hosts you have connected to the SAN.
  5. Install ESXi on the hosts.
  6. Create virtual machines and install guest operating systems.
  7. (Optional) Set up your system for VMware HA failover or for using Microsoft Clustering Services.
  8. Upgrade or modify your environment as needed.